The present invention relates, in general, to analog voltage conversion circuits, and more particularly, to circuits for converting a differential voltage to a differential current.
Previous implementation methods for differential voltage to differential current conversion circuits were limited by the transconductance of the transistors used to implement the circuit. The low transconductance of transistors used in previous implementations allowed the transistor's non-linear source impedance to become sufficiently large enough to effect other resistances in the circuit. Since the source impedance was non-linear, the output current produced by these circuits had a non-linear relation to the input voltage. Accordingly, it would be desirable to have a differential voltage to differential current conversion circuit that provided a linear output current that was proportional to the input voltage and was independent of the transconductance of the transistors used in the implementation.